* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: #f8f9fa;
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
}

.login-container {
  width: 100%;
  max-width: 420px;
  padding: 40px;
  background-color: #ffffff;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
  text-align: center;
}

.login-header {
  margin-bottom: 30px;
}

.login-title {
  font-size: 24px;
  font-weight: 600;
  color: #2c3e50;
  margin-bottom: 10px;
}

.login-subtitle {
  font-size: 14px;
  color: #6c757d;
}

.login-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  position: relative;
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid #e1e8ed;
  border-radius: 8px;
  font-size: 14px;
  transition: all 0.3s ease;
  background: #f8f9fa;
  outline: none;
}

.form-input:focus {
  border-color: #667eea;
  background: #ffffff;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.form-input::placeholder {
  color: #adb5bd;
}

.login-btn {
  background: linear-gradient(135deg, #667eea, #764ba2);
  border: none;
  color: white;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.3s ease;
  margin-top: 10px;
}

.login-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.login-btn:active {
  transform: translateY(0);
}

.login-options {
  margin-top: 20px;
  display: flex;
  justify-content: space-between;
  font-size: 13px;
}

.login-options a {
  color: #667eea;
  text-decoration: none;
  transition: all 0.2s ease;
}

.login-options a:hover {
  color: #764ba2;
  text-decoration: underline;
}

.login-divider {
  margin: 25px 0;
  display: flex;
  align-items: center;
  text-align: center;
}

.login-divider::before,
.login-divider::after {
  content: '';
  flex: 1;
  border-bottom: 1px solid #e1e8ed;
}

.login-divider-text {
  padding: 0 10px;
  color: #6c757d;
  font-size: 12px;
}

.social-login {
  display: flex;
  justify-content: center;
  gap: 15px;
}

.social-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid #e1e8ed;
  background: #ffffff;
  cursor: pointer;
  transition: all 0.3s ease;
}

.social-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.social-icon {
  width: 20px;
  height: 20px;
}

.error-message {
  color: #ff6b6b;
  font-size: 13px;
  margin-top: 5px;
  text-align: left;
  display: none;
}

.error-message.show {
  display: block;
}

/* 响应式设计 */
@media (max-width: 480px) {
  .login-container {
    padding: 30px 20px;
    max-width: 90%;
  }
}

/* 深色模式 */
body.dark-mode {
  background: linear-gradient(135deg, #1a1a1a 0%, #2c2c2c 100%);
}

.dark-mode .login-container {
  background-color: #1a1a1a;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
}

.dark-mode .login-title {
  color: #e1e1e1;
}

.dark-mode .login-subtitle {
  color: #a0a0a0;
}

.dark-mode .form-input {
  background: #2c2c2c;
  border-color: #444;
  color: #e1e1e1;
}

.dark-mode .form-input:focus {
  border-color: #667eea;
  background: #333;
}

.dark-mode .form-input::placeholder {
  color: #777;
}

.dark-mode .login-divider::before,
.dark-mode .login-divider::after {
  border-bottom: 1px solid #444;
}

.dark-mode .login-divider-text {
  color: #a0a0a0;
}

.dark-mode .social-btn {
  border: 1px solid #444;
  background: #2c2c2c;
}

.dark-mode .login-options a {
  color: #667eea;
}